What's the best Mexican restaurant in Seattle, Washington?

A couple, but for different reasons.

1) Agua Verde in the UDistrict. If you haven’t been there yet, it’s a funky little shacky place, right on the water. You can rent kayaks and paddle around while working up an appetite. The food is also great- they use as many organic ingredients, or sustainable ingredients as they can. It’s also really inexpensive. I always bring out-of-town guests there and highly suggest the fish tacos, yam tacos for vegetarians and the margaritas.

2) Carta de Oaxaca in Ballard. Great Oaxacan cuisine and the restaurant has a little bit of a cult following. Go early – it’s well worth the wait.

Cafe Moose in Ballard is amazing. Great food, great personality.

I also enjoy Baja Bistro on Beacon Hill. I really like their tacos de papa—tacos with mashed potatoes inside. Yum.

Both of those places feel more authentic to me than figbash’s suggestions. Fewer crowds of hipsters. But maybe that’s a silly distinction to make.

Know what, El Gallito on Capital Hill is pretty good, even though it’s kind of normal.
You get good food and no fancy regionalismo. Enjoy. Also, Tacos Guaymas on
Broadway near Union is excellent. Enormous “wet” burritos, lovely things to drink
ie. beers and big jars of horchata and tamarindo. Tacos de lengua can be had. People
are nice. And interesting paintings.